This invention relates to an exhaust system for a vehicle and more particularly to an improved compact, high efficiency exhaust system for vehicles that are designed primarily for operation by a single rider.
Many vehicles powered by internal combustion engines are designed to be operated primarily by a single rider. Powered vehicles normally embody at least one dirigible front wheel, a rear wheel, a frame that is adapted to provide a support for a rider and/or passengers and which supports a power plant, normally an internal combustion engine, for powering at least one of the vehicle wheels. If the vehicle is designed to be operated by, and normally accommodate only, a single rider, the vehicle has a very compact configuration. As such, it is very difficult to provide an effective silencing arrangement for the exhaust of the internal combustion engine. Motorcycles are typical examples of vehicles of the type which provide difficulty in accomplishing efficient silencing in the very small area available to provide all of the necessary components and also an efficient silencing system. One of the most effective silencing devices for internal combustion engines is the use of an expansion chamber in the exhaust system. When the vehicle is extremely compact, as in the case of single rider vehicles such as motorcycles, it is difficult to provide an expansion chamber of sufficient volume within the available area and still permit a compact and yet serviceable arrangement.
Most exhaust systems for vehicles of this type embody one or more exhaust pipes that extend from the exhaust ports of the engine and which terminate in an exhaust device such as a muffler or the like which includes an expansion chamber. If the expansion chamber is to have sufficient volume and the vehicle is as compact as desired, it is extremely difficult to appropriately position the exhaust expansion chamber so that it will not interfere with the other components of the vehicle, so that it will have sufficient volume, and so that it can be positioned so that it will not interfere with the rider of the vehicle. Most, if not all, motorcycles or other vehicles of this type, therefore, position an expansion chamber to the rear of the engine. As a result, it is necessary to increase the wheel base of the vehicle so as to accommodate the expansion chamber. Alternatively, the expansion chamber must be positioned rearwardly of the engine and, therefore, the overall width of the vehicle is undesirably increased and, furthermore, the exhaust system is lengthened consideration.
It is, therefore, a principal object of this invention to provide an exhaust system for a vehicle that permits the use of a large volume expansion chamber and yet which permits a compact configuration.
It is another object of this invention to provide an exhaust system for a vehicle that permits the use of a large expansion chamber and which does not increase the length of the vehicle and/or the exhaust system.
It is a still further object of this invention to provide an improved exhaust system for a vehicle which permits a relatively large and yet forwardly position exhaust system.
In a vehicle such a motorcycle or other types of off the road vehicles which offer a compact configuration and which are designed to accommodate only a single rider, it is very difficult to provide an enlarged expansion chamber within the confines the main frame of the vehicle and between the front and rear vehicle wheels. As a result, it has been proposed to provide exhaust systems for vehicles that employ expansion chambers that are located in areas which are difficult to service and/or necessitate elongation of the vehicle.
It is, therefore, still a further object of this invention to provide an exhaust system for a vehicle embodying an expansion chamber that can be conveniently positioned between the front and rear wheels and which will still have a large volume.
In connection with certain vehicles such as motorcycles or the like wherein some of the exhaust system is exposed externally, it has been the practice to provide a double exhaust pipe leading to the exhaust chamber so as to insure that the exhaust pipe will not become discolored in use. That is, in a conventional type of exhaust system for this type of vehicle, it has been prpposed to provide a heat resistant interior pipe and an exterior pipe that is insulated from the interior pipe and which is constructed in such a way that it will not become discolored from the heat of the exhaust gases. Of course, the use of such double pipe systems raises a numer of problems in designing, forming and assembling the exhaust system.
It is, therefore, still a further object of this invention to provide an exhaust system for a vehicle in which the exhaust pipe is exposed and yet will not become discolored due to the heat and use of the system.